The telephone network has long been utilized as a medium for broadcasting messages of general interest to telephone customers. Thus, customers can dial preassigned directory numbers to receive recorded information such as weather reports, stock quotations, the time-of-day, scores of sporting events, etc. If the recorded announcements are in the nature of a public service such as weather reports, time-of-day, etc., and are under control of the telephone company, measures can be taken to safeguard the announcement system so that unauthorized messages are not inadvertently broadcast over the network. Thus, any changes in announcements would be permitted only by authorized telephone company personnel who have access to the announcement equipment.
The announcement service, however, may also be offered to subscribers who wish to broadcast announcements of a more commercial nature such as stock quotations, promotional advertisements, and the like. With this service, it is desirable to permit an authorized subscriber (referred to herein as a producer) to make changes in his announcements by calling directly over the regular telephone network.
There are known systems which employ safety measures to preclude unauthorized announcements and yet permit a producer to make announcement changes over the network from a telephone station. With these arrangements, the producer can dial a special access code from a station to gain access to the announcement system. Once gaining access to the system, the producer dials special unlocking codes in order to update a particular announcement. After the new announcement has been recorded, the announcement is played back over the same telephone connection to permit the producer to verify the message for correctness and transmission quality. While certain safeguards are employed in these arrangements, it is obvious that anyone having knowledge of the unlocking and access codes can change announcements at will without the producer's permission. Thus, an unauthorized person could replace a legitimate announcement with material that is objectionable or detrimental to the producer.